This application relates to replaceable consumable devices for use with printing apparatus having the ability to read and write data relating to a quantity of marking material contained within the replaceable consumable. More particularly, the subject application relates to ink and toner cartridges having an enhanced storage capacity ink or toner usage efficiency and electronics for interfacing with the associated printing apparatus to store the data relating to a quantity of the marking material. However, it is to be appreciated that the present exemplary embodiments may find use in related and other environments and applications where replaceable cartridges holding consumable materials are used.
It is generally well known in the art to provide ink and toner cartridges with electronic devices storing various data which is useful to the printing device in executing print functions. One form of data used in the past includes data representative of a type of marking material contained in the cartridge. That data is first read by the printing apparatus from electronics carried on the cartridge and is then used to set operational printing parameters within the printing apparatus. This technique best assures that any changes in the chemistry or composition of the marking material are accommodated in the printing apparatus such as by adjusting an amount of power supplied to print heads or fuser stations for generating printed documents having a high quality.
Another form of data commonly stored in electronic devices carried on cartridges includes marking material quantity data. Data of this type is essentially data representative of either an amount of marking material consumed from the cartridge or an amount of marking material remaining in the cartridge at any given time. Typically, both of these were represented as percentages of a completely full cartridge capacity value or of a completely empty cartridge capacity value. In either case, the marking material quantity data is used directly by the printing application to determine a projected printed page capability by calculating a product of a stored value representative of a full quantity of material with the percentage data value obtained from the cartridge multiplied by a constant representative of an average page count per given unit of marking material. During a printer initialization cycle, the marking material quantity data is retrieved from the electronic storage portion of the cartridge and copied into a memory location resident in the printing apparatus. During ensuing printing operations, the printing apparatus either deducts from the remaining material quantity data or adds to the marking material consumed data to keep an accurate account of the depletion state of the consumable cartridge. In some prior art printer and consumable cartridge systems, the printer periodically writes the marking material quantity data to the cartridge memory according to a regular predetermined schedule. In other prior art systems, the printing apparatus simply writes back the consumable quantity data during a power down cycle.
It is important for printing devices to suspend or terminate printing operations well before a complete exhaustion of the marking material. In some cases, such as in ink jet printing, the marking fluid is used to cool the printhead and without it, damage would occur. In other examples, it is important to discourage the formation of bubbles entrained in the fluid conduit system conveying marking material between the replaceable consumable and the printing device. It is important there as well to terminate printing operations well before those systems run dry. In toner based printing systems, it is important to be sure that the printing apparatus always has a supply of toner so that the developer and fusing stations are not adversely affected such as when those systems run dry.
Many original equipment manufacturers (OEMs) adopt a conservative approach to preventing their printing apparatus from running dry. One example of such an approach includes a method of monitoring of the marking material quantity data and terminating printing operations when the marking material quantity data reaches a minimum threshold value, typically of about 20% marking material remaining. As an example, in marking systems with cartridges holding 20 ml. of ink, the printing is terminated when the ink remaining data reaches about 20% of the total or, when the amount of ink remaining in the cartridge is about 4 ml. Of course, this is wasteful but, as noted above, provides an extremely conservative approach. This large amount of ink remaining in the cartridge after the printing apparatus has determined the cartridge to be useless is a significant amount of otherwise valuable product which was paid for by the consumer and which would eventually form part of a landfill.
Oftentimes consumers and other owners of ink cartridges desire to fill those cartridges with marking material in excess of an original quantity of marking material typically supplied by the OEM. In the example above, the consumer might try to fill the cartridge with 24 ml. of ink, rather than with the standard 20 ml. supplied by OEM. It would seem to the consumer that this would be useful for purposes of minimizing the amount of time spent in replacing cartridges and maximizing the page count between cartridge changes to enhance business productivity. However, simply adding additional marking material to the cartridge has no effect on the total number of pages of printed production from that cartridge because, as noted above, the printing apparatus typically decrement/increment the marking material data represented as a percentage of a completely filled or a completely empty state until a predetermined threshold is reached whereupon further printing operations are terminated. In the above example, the printer is programmed to behave as if 20 ml. are present and to consume up to 16 ml., thus leaving 8 ml. of unused ink in the tank. This is extremely wasteful because the additional amount of marking material added by the consumer or owner is not used and, further, the original amount of marking material as specified by the OEM is not used either.
However, it remains highly desirable for consumers and owners of those cartridges to refill them at a capacity in excess of the OEM specifications. Typically this refill is performed by simply adding additional marking material in void spaces in the original unaltered cartridge. Another approach is to modify the OEM cartridge slightly by adding a large bin or storage capacity structure to accommodate additional marking material. Thereafter, the electronics on the cartridges are reset to a full value even tough a substantial portion of the material has been depleted. This is, of course, risky because as explained above, the print heads can be overheated and damaged.
In either case, again, it is highly desirable to provide an enhanced marking material capacity.